01 Sintra & Pena Palace
The one Lisbon ticket that genuinely needs planning, from €29. Pena Palace sells timed entry and the mid-morning slots go days ahead from May to September; Quinta da Regaleira next door does not, which is why most small-group tours pair them. Sintra is a hill town with one road — going by organised trip rather than by train and taxi is the difference between three sites and one.
02 Belém
Cheap to enter and slow to reach: the monastery, the tower and the pastry shop are all within a few hundred metres, and the queue is at the pastry shop. Go early, take the tram out and the ferry or an e-bike back. Tickets are usually available on the day outside August.
03 Alfama & the Fado houses
Not a ticket so much as an evening. The fado houses that admit walk-ins are the ones the guides avoid; anything worth hearing takes a booking, usually with dinner attached. Combined food-and-fado walks rate well here because they solve the ordering problem for you.